A 55-Year-Old Man Undergoing Evaluation for Fatigue and Exertional Dyspnea

question 711

Multiple Choice

A 55-year-old man undergoing evaluation for fatigue and exertional dyspnea is diagnosed with macrocytic anemia.  Upper gastrointestinal endoscopy is consistent with atrophic gastritis.  He is started on intramuscular cyanocobalamin, with the resulting changes shown in the graph below. The blue curve most likely corresponds to which of the following parameters?

• A)Erythrocyte count
• B)Gastrin
• C)Haptoglobin
• D)Methylmalonic acid
• E)Reticulocyte count

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Definitions:

Mean Difference

The average difference between two sets of data points, often used in comparing the means from two samples.

Independent Populations

Populations that have no influence on one another, implying that the selection from one population does not affect the selection from another.

Significance Level

A threshold in hypothesis testing that determines whether the observed results are statistically significant.

Engine Wear

The gradual degradation and wear of engine components due to friction, heat, and use over time, affecting performance and lifespan.